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<b>DbEnv::set_lg_max</b>
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<b><pre>
#include &lt;db_cxx.h&gt;
<p>
int
DbEnv::set_lg_max(u_int32_t lg_max);
<p>
int
DbEnv::get_lg_max(u_int32_t *);
</pre></b>
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<b>Description: DbEnv::set_lg_max</b>
<p>Set the maximum size of a single file in the log, in bytes.  Because
<a href="../api_cxx/lsn_class.html">DbLsn</a> file offsets are unsigned four-byte values, the set
value may not be larger than the maximum unsigned four-byte value.</p>
<p>When the logging subsystem is configured for on-disk logging, the
default size of a log file is 10MB.</p>
<p>When the logging subsystem is configured for in-memory logging, the
default size of a log file is 256KB.  In addition, the configured log
buffer size must be larger than the log file size.  (The logging
subsystem divides memory configured for in-memory log records into
"files", as database environments configured for in-memory log records
may exchange log records with other members of a replication group, and
those members may be configured to store log records on-disk.)  When
choosing log buffer and file sizes for in-memory logs, applications
should ensure the in-memory log buffer size is large enough that no
transaction will ever span the entire buffer, and avoid a state where
the in-memory buffer is full and no space can be freed because a
transaction that started in the first log "file" is still active.</p>
<p>See <a href="../ref/log/limits.html">Log File Limits</a> for more
information.</p>
<p>The database environment's log file size may also be configured using the
environment's <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file.  The syntax of the entry in that
file is a single line with the string "set_lg_max", one or more whitespace
characters, and the size in bytes.
Because the <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment
is opened, it will silently overrule configuration done before that
time.</p>
<p>The DbEnv::set_lg_max method configures a database environment, not only operations
performed using the specified <a href="../api_cxx/env_class.html">DbEnv</a> handle.</p>
<p>The DbEnv::set_lg_max method may be called at any time during the life of the
application.</p>
If no size is specified by the application, the size last specified for
the database region will be used, or if no database region previously
existed, the default will be used.
<p>The DbEnv::set_lg_max method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
 <b>lg_max</b><ul compact><li>The <b>lg_max</b> parameter is the size of a single log file, in bytes.</ul>
<br>
<br><b>Errors</b>
<p>The DbEnv::set_lg_max method
may fail and throw
<a href="../api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:</p>
<br>
<b>EINVAL</b><ul compact><li>If the method was called after <a href="../api_cxx/env_open.html">DbEnv::open</a> was called;
the size of the log file is less than four times the size of the in-memory
log buffer;
The specified log file size was too large; or if an
invalid flag value or parameter was specified.</ul>
<br>
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<b>Description: DbEnv::get_lg_max</b>
<p>The DbEnv::get_lg_max method returns the maximum log file size.</p>
<p>The DbEnv::get_lg_max method may be called at any time during the life of the
application.</p>
<p>The DbEnv::get_lg_max method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
 <b>lg_maxp</b><ul compact><li>The DbEnv::get_lg_max method returns  the
maximum log file size in <b>lg_maxp</b>.</ul>
<br>
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<br><b>Class</b>
<a href="../api_cxx/env_class.html">DbEnv</a>, <a href="../api_cxx/logc_class.html">DbLogc</a>, <a href="../api_cxx/lsn_class.html">DbLsn</a>
<br><b>See Also</b>
<a href="../api_cxx/log_list.html">Logging Subsystem and Related Methods</a>
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